1 CLONAL HYPERPLASIA OF CYCLIN D1+ MANTLE LYMPHOCYTES IN AN ASYMPTOMATIC PATIENT: A NEW ENTITY OR AN EARLY STAGE EVENT IN THE DEVELOPMENT OF A MANTLE CELL LYMPHOMA?

Mantle cell lymphoma (MCL) is a B-cell neoplasm with a relatively aggressive clinical course. There is a subgroup of patients with histological, immunophenotypical and genetic characteristics corresponding to a MCL that present with atypical lymphocytes in peripheral blood (PB), with or without lymphocytosis, lymphadenopathy or splenomegaly and pursue a benign clinical course. In these cases, it is frequent to find mutated immunoglobulin heavy chain genes and lack of CD5 expression. In patients with lymphadenopathy, a mantle cell growth pattern is observed in the biopsy. It is uncertain whether these cases represent an early stage event in the development of MCL, an indolent form of MCL, or a newly recognized lymphoproliferative disorder not well characterized yet. We report an asymptomatic elderly patient who presented with a single submandibular adenopathy that was excised due to esthetic reasons. The adenopathy biopsy showed the presence of t(11;14)(q13;q32) and histology and immunophenotype consistent with a MCL. The abnormal lymphoid population was also detected in PB and in bone marrow. The patient has remained asymptomatic for five years without receiving any therapy. The existence of these asymptomatic cases with an indolent clinical course should induce to a strict clinical judgement in terms of terapeutic decisions